summaryrefslogtreecommitdiff
path: root/drivers/mtd/nand/raw/mtk_ecc.c
blob: 74595b644b7cd7beb619b27e0efe7521ab9761b6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
// SPDX-License-Identifier: GPL-2.0 OR MIT
/*
 * MTK ECC controller driver.
 * Copyright (C) 2016  MediaTek Inc.
 * Authors:	Xiaolei Li		<xiaolei.li@mediatek.com>
 *		Jorge Ramirez-Ortiz	<jorge.ramirez-ortiz@linaro.org>
 */

#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/iopoll.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/mutex.h>

#include "mtk_ecc.h"

#define ECC_IDLE_MASK		BIT(0)
#define ECC_IRQ_EN		BIT(0)
#define ECC_PG_IRQ_SEL		BIT(1)
#define ECC_OP_ENABLE		(1)
#define ECC_OP_DISABLE		(0)

#define ECC_ENCCON		(0x00)
#define ECC_ENCCNFG		(0x04)
#define		ECC_MS_SHIFT		(16)
#define ECC_ENCDIADDR		(0x08)
#define ECC_ENCIDLE		(0x0C)
#define ECC_DECCON		(0x100)
#define ECC_DECCNFG		(0x104)
#define		DEC_EMPTY_EN		BIT(31)
#define		DEC_CNFG_CORRECT	(0x3 << 12)
#define ECC_DECIDLE		(0x10C)
#define ECC_DECENUM0		(0x114)

#define ECC_TIMEOUT		(500000)

#define ECC_IDLE_REG(op)	((op) == ECC_ENCODE ? ECC_ENCIDLE : ECC_DECIDLE)
#define ECC_CTL_REG(op)		((op) == ECC_ENCODE ? ECC_ENCCON : ECC_DECCON)

struct mtk_ecc_caps {
	u32 err_mask;
	const u8 *ecc_strength;
	const u32 *ecc_regs;
	u8 num_ecc_strength;
	u8 ecc_mode_shift;
	u32 parity_bits;
	int pg_irq_sel;
};

struct mtk_ecc {
	struct device *dev;
	const struct mtk_ecc_caps *caps;
	void __iomem *regs;
	struct clk *clk;

	struct completion done;
	struct mutex lock;
	u32 sectors;

	u8 *eccdata;
};

/* ecc strength that each IP supports */
static const u8 ecc_strength_mt2701[] = {
	4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36,
	40, 44, 48, 52, 56, 60
};

static const u8 ecc_strength_mt2712[] = {
	4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36,
	40, 44, 48, 52, 56, 60, 68, 72, 80
};

static const u8 ecc_strength_mt7622[] = {
	4, 6, 8, 10, 12, 14, 16
};

enum mtk_ecc_regs {
	ECC_ENCPAR00,
	ECC_ENCIRQ_EN,
	ECC_ENCIRQ_STA,
	ECC_DECDONE,
	ECC_DECIRQ_EN,
	ECC_DECIRQ_STA,
};

static int mt2701_ecc_regs[] = {
	[ECC_ENCPAR00] =        0x10,
	[ECC_ENCIRQ_EN] =       0x80,
	[ECC_ENCIRQ_STA] =      0x84,
	[ECC_DECDONE] =         0x124,
	[ECC_DECIRQ_EN] =       0x200,
	[ECC_DECIRQ_STA] =      0x204,
};

static int mt2712_ecc_regs[] = {
	[ECC_ENCPAR00] =        0x300,
	[ECC_ENCIRQ_EN] =       0x80,
	[ECC_ENCIRQ_STA] =      0x84,
	[ECC_DECDONE] =         0x124,
	[ECC_DECIRQ_EN] =       0x200,
	[ECC_DECIRQ_STA] =      0x204,
};

static int mt7622_ecc_regs[] = {
	[ECC_ENCPAR00] =        0x10,
	[ECC_ENCIRQ_EN] =       0x30,
	[ECC_ENCIRQ_STA] =      0x34,
	[ECC_DECDONE] =         0x11c,
	[ECC_DECIRQ_EN] =       0x140,
	[ECC_DECIRQ_STA] =      0x144,
};

static inline void mtk_ecc_wait_idle(struct mtk_ecc *ecc,
				     enum mtk_ecc_operation op)
{
	struct device *dev = ecc->dev;
	u32 val;
	int ret;

	ret = readl_poll_timeout_atomic(ecc->regs + ECC_IDLE_REG(op), val,
					val & ECC_IDLE_MASK,
					10, ECC_TIMEOUT);
	if (ret)
		dev_warn(dev, "%s NOT idle\n",
			 op == ECC_ENCODE ? "encoder" : "decoder");
}

static irqreturn_t mtk_ecc_irq(int irq, void *id)
{
	struct mtk_ecc *ecc = id;
	u32 dec, enc;

	dec = readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECIRQ_STA])
		    & ECC_IRQ_EN;
	if (dec) {
		dec = readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECDONE]);
		if (dec & ecc->sectors) {
			/*
			 * Clear decode IRQ status once again to ensure that
			 * there will be no extra IRQ.
			 */
			readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECIRQ_STA]);
			ecc->sectors = 0;
			complete(&ecc->done);
		} else {
			return IRQ_HANDLED;
		}
	} else {
		enc = readl(ecc->regs + ecc->caps->ecc_regs[ECC_ENCIRQ_STA])
		      & ECC_IRQ_EN;
		if (enc)
			complete(&ecc->done);
		else
			return IRQ_NONE;
	}

	return IRQ_HANDLED;
}

static int mtk_ecc_config(struct mtk_ecc *ecc, struct mtk_ecc_config *config)
{
	u32 ecc_bit, dec_sz, enc_sz;
	u32 reg, i;

	for (i = 0; i < ecc->caps->num_ecc_strength; i++) {
		if (ecc->caps->ecc_strength[i] == config->strength)
			break;
	}

	if (i == ecc->caps->num_ecc_strength) {
		dev_err(ecc->dev, "invalid ecc strength %d\n",
			config->strength);
		return -EINVAL;
	}

	ecc_bit = i;

	if (config->op == ECC_ENCODE) {
		/* configure ECC encoder (in bits) */
		enc_sz = config->len << 3;

		reg = ecc_bit | (config->mode << ecc->caps->ecc_mode_shift);
		reg |= (enc_sz << ECC_MS_SHIFT);
		writel(reg, ecc->regs + ECC_ENCCNFG);

		if (config->mode != ECC_NFI_MODE)
			writel(lower_32_bits(config->addr),
			       ecc->regs + ECC_ENCDIADDR);

	} else {
		/* configure ECC decoder (in bits) */
		dec_sz = (config->len << 3) +
			 config->strength * ecc->caps->parity_bits;

		reg = ecc_bit | (config->mode << ecc->caps->ecc_mode_shift);
		reg |= (dec_sz << ECC_MS_SHIFT) | DEC_CNFG_CORRECT;
		reg |= DEC_EMPTY_EN;
		writel(reg, ecc->regs + ECC_DECCNFG);

		if (config->sectors)
			ecc->sectors = 1 << (config->sectors - 1);
	}

	return 0;
}

void mtk_ecc_get_stats(struct mtk_ecc *ecc, struct mtk_ecc_stats *stats,
		       int sectors)
{
	u32 offset, i, err;
	u32 bitflips = 0;

	stats->corrected = 0;
	stats->failed = 0;

	for (i = 0; i < sectors; i++) {
		offset = (i >> 2) << 2;
		err = readl(ecc->regs + ECC_DECENUM0 + offset);
		err = err >> ((i % 4) * 8);
		err &= ecc->caps->err_mask;
		if (err == ecc->caps->err_mask) {
			/* uncorrectable errors */
			stats->failed++;
			continue;
		}

		stats->corrected += err;
		bitflips = max_t(u32, bitflips, err);
	}

	stats->bitflips = bitflips;
}
EXPORT_SYMBOL(mtk_ecc_get_stats);

void mtk_ecc_release(struct mtk_ecc *ecc)
{
	clk_disable_unprepare(ecc->clk);
	put_device(ecc->dev);
}
EXPORT_SYMBOL(mtk_ecc_release);

static void mtk_ecc_hw_init(struct mtk_ecc *ecc)
{
	mtk_ecc_wait_idle(ecc, ECC_ENCODE);
	writew(ECC_OP_DISABLE, ecc->regs + ECC_ENCCON);

	mtk_ecc_wait_idle(ecc, ECC_DECODE);
	writel(ECC_OP_DISABLE, ecc->regs + ECC_DECCON);
}

static struct mtk_ecc *mtk_ecc_get(struct device_node *np)
{
	struct platform_device *pdev;
	struct mtk_ecc *ecc;

	pdev = of_find_device_by_node(np);
	if (!pdev)
		return ERR_PTR(-EPROBE_DEFER);

	ecc = platform_get_drvdata(pdev);
	if (!ecc) {
		put_device(&pdev->dev);
		return ERR_PTR(-EPROBE_DEFER);
	}

	clk_prepare_enable(ecc->clk);
	mtk_ecc_hw_init(ecc);

	return ecc;
}

struct mtk_ecc *of_mtk_ecc_get(struct device_node *of_node)
{
	struct mtk_ecc *ecc = NULL;
	struct device_node *np;

	np = of_parse_phandle(of_node, "ecc-engine", 0);
	if (np) {
		ecc = mtk_ecc_get(np);
		of_node_put(np);
	}

	return ecc;
}
EXPORT_SYMBOL(of_mtk_ecc_get);

int mtk_ecc_enable(struct mtk_ecc *ecc, struct mtk_ecc_config *config)
{
	enum mtk_ecc_operation op = config->op;
	u16 reg_val;
	int ret;

	ret = mutex_lock_interruptible(&ecc->lock);
	if (ret) {
		dev_err(ecc->dev, "interrupted when attempting to lock\n");
		return ret;
	}

	mtk_ecc_wait_idle(ecc, op);

	ret = mtk_ecc_config(ecc, config);
	if (ret) {
		mutex_unlock(&ecc->lock);
		return ret;
	}

	if (config->mode != ECC_NFI_MODE || op != ECC_ENCODE) {
		init_completion(&ecc->done);
		reg_val = ECC_IRQ_EN;
		/*
		 * For ECC_NFI_MODE, if ecc->caps->pg_irq_sel is 1, then it
		 * means this chip can only generate one ecc irq during page
		 * read / write. If is 0, generate one ecc irq each ecc step.
		 */
		if (ecc->caps->pg_irq_sel && config->mode == ECC_NFI_MODE)
			reg_val |= ECC_PG_IRQ_SEL;
		if (op == ECC_ENCODE)
			writew(reg_val, ecc->regs +
			       ecc->caps->ecc_regs[ECC_ENCIRQ_EN]);
		else
			writew(reg_val, ecc->regs +
			       ecc->caps->ecc_regs[ECC_DECIRQ_EN]);
	}

	writew(ECC_OP_ENABLE, ecc->regs + ECC_CTL_REG(op));

	return 0;
}
EXPORT_SYMBOL(mtk_ecc_enable);

void mtk_ecc_disable(struct mtk_ecc *ecc)
{
	enum mtk_ecc_operation op = ECC_ENCODE;

	/* find out the running operation */
	if (readw(ecc->regs + ECC_CTL_REG(op)) != ECC_OP_ENABLE)
		op = ECC_DECODE;

	/* disable it */
	mtk_ecc_wait_idle(ecc, op);
	if (op == ECC_DECODE) {
		/*
		 * Clear decode IRQ status in case there is a timeout to wait
		 * decode IRQ.
		 */
		readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECDONE]);
		writew(0, ecc->regs + ecc->caps->ecc_regs[ECC_DECIRQ_EN]);
	} else {
		writew(0, ecc->regs + ecc->caps->ecc_regs[ECC_ENCIRQ_EN]);
	}

	writew(ECC_OP_DISABLE, ecc->regs + ECC_CTL_REG(op));

	mutex_unlock(&ecc->lock);
}
EXPORT_SYMBOL(mtk_ecc_disable);

int mtk_ecc_wait_done(struct mtk_ecc *ecc, enum mtk_ecc_operation op)
{
	int ret;

	ret = wait_for_completion_timeout(&ecc->done, msecs_to_jiffies(500));
	if (!ret) {
		dev_err(ecc->dev, "%s timeout - interrupt did not arrive)\n",
			(op == ECC_ENCODE) ? "encoder" : "decoder");
		return -ETIMEDOUT;
	}

	return 0;
}
EXPORT_SYMBOL(mtk_ecc_wait_done);

int mtk_ecc_encode(struct mtk_ecc *ecc, struct mtk_ecc_config *config,
		   u8 *data, u32 bytes)
{
	dma_addr_t addr;
	u32 len;
	int ret;

	addr = dma_map_single(ecc->dev, data, bytes, DMA_TO_DEVICE);
	ret = dma_mapping_error(ecc->dev, addr);
	if (ret) {
		dev_err(ecc->dev, "dma mapping error\n");
		return -EINVAL;
	}

	config->op = ECC_ENCODE;
	config->addr = addr;
	ret = mtk_ecc_enable(ecc, config);
	if (ret) {
		dma_unmap_single(ecc->dev, addr, bytes, DMA_TO_DEVICE);
		return ret;
	}

	ret = mtk_ecc_wait_done(ecc, ECC_ENCODE);
	if (ret)
		goto timeout;

	mtk_ecc_wait_idle(ecc, ECC_ENCODE);

	/* Program ECC bytes to OOB: per sector oob = FDM + ECC + SPARE */
	len = (config->strength * ecc->caps->parity_bits + 7) >> 3;

	/* write the parity bytes generated by the ECC back to temp buffer */
	__ioread32_copy(ecc->eccdata,
			ecc->regs + ecc->caps->ecc_regs[ECC_ENCPAR00],
			round_up(len, 4));

	/* copy into possibly unaligned OOB region with actual length */
	memcpy(data + bytes, ecc->eccdata, len);
timeout:

	dma_unmap_single(ecc->dev, addr, bytes, DMA_TO_DEVICE);
	mtk_ecc_disable(ecc);

	return ret;
}
EXPORT_SYMBOL(mtk_ecc_encode);

void mtk_ecc_adjust_strength(struct mtk_ecc *ecc, u32 *p)
{
	const u8 *ecc_strength = ecc->caps->ecc_strength;
	int i;

	for (i = 0; i < ecc->caps->num_ecc_strength; i++) {
		if (*p <= ecc_strength[i]) {
			if (!i)
				*p = ecc_strength[i];
			else if (*p != ecc_strength[i])
				*p = ecc_strength[i - 1];
			return;
		}
	}

	*p = ecc_strength[ecc->caps->num_ecc_strength - 1];
}
EXPORT_SYMBOL(mtk_ecc_adjust_strength);

unsigned int mtk_ecc_get_parity_bits(struct mtk_ecc *ecc)
{
	return ecc->caps->parity_bits;
}
EXPORT_SYMBOL(mtk_ecc_get_parity_bits);

static const struct mtk_ecc_caps mtk_ecc_caps_mt2701 = {
	.err_mask = 0x3f,
	.ecc_strength = ecc_strength_mt2701,
	.ecc_regs = mt2701_ecc_regs,
	.num_ecc_strength = 20,
	.ecc_mode_shift = 5,
	.parity_bits = 14,
	.pg_irq_sel = 0,
};

static const struct mtk_ecc_caps mtk_ecc_caps_mt2712 = {
	.err_mask = 0x7f,
	.ecc_strength = ecc_strength_mt2712,
	.ecc_regs = mt2712_ecc_regs,
	.num_ecc_strength = 23,
	.ecc_mode_shift = 5,
	.parity_bits = 14,
	.pg_irq_sel = 1,
};

static const struct mtk_ecc_caps mtk_ecc_caps_mt7622 = {
	.err_mask = 0x3f,
	.ecc_strength = ecc_strength_mt7622,
	.ecc_regs = mt7622_ecc_regs,
	.num_ecc_strength = 7,
	.ecc_mode_shift = 4,
	.parity_bits = 13,
	.pg_irq_sel = 0,
};

static const struct of_device_id mtk_ecc_dt_match[] = {
	{
		.compatible = "mediatek,mt2701-ecc",
		.data = &mtk_ecc_caps_mt2701,
	}, {
		.compatible = "mediatek,mt2712-ecc",
		.data = &mtk_ecc_caps_mt2712,
	}, {
		.compatible = "mediatek,mt7622-ecc",
		.data = &mtk_ecc_caps_mt7622,
	},
	{},
};

static int mtk_ecc_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct mtk_ecc *ecc;
	struct resource *res;
	u32 max_eccdata_size;
	int irq, ret;

	ecc = devm_kzalloc(dev, sizeof(*ecc), GFP_KERNEL);
	if (!ecc)
		return -ENOMEM;

	ecc->caps = of_device_get_match_data(dev);

	max_eccdata_size = ecc->caps->num_ecc_strength - 1;
	max_eccdata_size = ecc->caps->ecc_strength[max_eccdata_size];
	max_eccdata_size = (max_eccdata_size * ecc->caps->parity_bits + 7) >> 3;
	max_eccdata_size = round_up(max_eccdata_size, 4);
	ecc->eccdata = devm_kzalloc(dev, max_eccdata_size, GFP_KERNEL);
	if (!ecc->eccdata)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	ecc->regs = devm_ioremap_resource(dev, res);
	if (IS_ERR(ecc->regs)) {
		dev_err(dev, "failed to map regs: %ld\n", PTR_ERR(ecc->regs));
		return PTR_ERR(ecc->regs);
	}

	ecc->clk = devm_clk_get(dev, NULL);
	if (IS_ERR(ecc->clk)) {
		dev_err(dev, "failed to get clock: %ld\n", PTR_ERR(ecc->clk));
		return PTR_ERR(ecc->clk);
	}

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		dev_err(dev, "failed to get irq: %d\n", irq);
		return irq;
	}

	ret = dma_set_mask(dev, DMA_BIT_MASK(32));
	if (ret) {
		dev_err(dev, "failed to set DMA mask\n");
		return ret;
	}

	ret = devm_request_irq(dev, irq, mtk_ecc_irq, 0x0, "mtk-ecc", ecc);
	if (ret) {
		dev_err(dev, "failed to request irq\n");
		return -EINVAL;
	}

	ecc->dev = dev;
	mutex_init(&ecc->lock);
	platform_set_drvdata(pdev, ecc);
	dev_info(dev, "probed\n");

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int mtk_ecc_suspend(struct device *dev)
{
	struct mtk_ecc *ecc = dev_get_drvdata(dev);

	clk_disable_unprepare(ecc->clk);

	return 0;
}

static int mtk_ecc_resume(struct device *dev)
{
	struct mtk_ecc *ecc = dev_get_drvdata(dev);
	int ret;

	ret = clk_prepare_enable(ecc->clk);
	if (ret) {
		dev_err(dev, "failed to enable clk\n");
		return ret;
	}

	return 0;
}

static SIMPLE_DEV_PM_OPS(mtk_ecc_pm_ops, mtk_ecc_suspend, mtk_ecc_resume);
#endif

MODULE_DEVICE_TABLE(of, mtk_ecc_dt_match);

static struct platform_driver mtk_ecc_driver = {
	.probe  = mtk_ecc_probe,
	.driver = {
		.name  = "mtk-ecc",
		.of_match_table = of_match_ptr(mtk_ecc_dt_match),
#ifdef CONFIG_PM_SLEEP
		.pm = &mtk_ecc_pm_ops,
#endif
	},
};

module_platform_driver(mtk_ecc_driver);

MODULE_AUTHOR("Xiaolei Li <xiaolei.li@mediatek.com>");
MODULE_DESCRIPTION("MTK Nand ECC Driver");
MODULE_LICENSE("Dual MIT/GPL");